JP Publication of Application No. 2004-203546 (Patent Document 1) describes an article transfer device for moving articles along a transfer direction. More specifically, the article transfer device described in Patent Document 1 includes a contact member that contacts an article and moves the article by moving along the transfer direction, an actuating mechanism which includes an electric motor for moving the contact member along the transfer direction, and an actuation controller which controls the action of the actuating mechanism. And the contact member which is located away from a stationary article is moved by the actuating mechanism and is caused to come into contact with the article. And the article is moved along the transfer direction by moving the contact member, with the contact member in contact with the article. In order to move the article quickly during this operation, it is necessary to increase the moving speed of the contact member.
However, the impact force on the article would be large if the contact member comes into contact with the articles at a large speed, which may cause problems, such as the article being deformed and/or noise being generated. In the invention described in Patent Document 1, a speed control of the electric motor is performed in which the contact member is moved at a low speed at first, and the moving speed of the contact member is increased at the moment of, or after, the contact member coming into contact with the article. Thus, an attempt has been made to quickly transfer articles while reducing impact force applied on the articles. Note that such a speed control is commonly performed through a feedback control in which command values are provided to the electric motor that depend on the error between the actual rotational speed of the electric motor and a target rotational speed and that would cause the actual rotational speed of the electric motor to approach the target rotational speed, for example.